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All capacitors great and small, and depotting question

     I had the good fortune to obtain a scrap roll of 14" wide, 2 mil 
     think, 300 foot FEP (Fluorinated Ethylene Propylene).  FEP is one of 
     the forms of Teflon, and it has properties which suggest it would be 
     suitable for use in making caps for TC service.
     
     Dissipation Factor (1 MHz): 0.0006
     Dielectric Constant: 2.0
     Dielectric Strength (DC, 1 mil): 6500 V/mil !!!
     
     WRT dielectric strength, the value per mil decreases as the film 
     thickness decreases (the 20 mil film is rated at only 1800 V/mil).  
     Now, I know 10 sheets of 2 mil film will have a greater dielectric 
     strength than one sheet of 20 mil material (this issue has been 
     addressed on this list many times), but may one simply add the 
     dielectric strength ratings of each stacked sheet, or is there a 
     diminishing return as a new layer is added?
     
     I would like to conservatively derate the film to 2000 V/mil and make 
     strings of 5 capacitors in series, each with two 2 mil layers of FEP, 
     for service with a TC driven with a 15,000V NST.
     
     What do you think?
     
     Also, I received a quote for pulse caps which I think are suitable for 
     a MMC.  The manufacturer is Seacor, the type is KP25, and the value is 
     0.047uF, 1600 VDC.  The caps are $0.79 each, with a minimum order of 
     500 pieces.  Anyone interested in a group buy?  Data can be found at 
     the URL http://www.seacorinc-dot-com/Tables/high_pulse.htm  The company 
     claims the KP25 family is a cross for the Wima FKP1 family.  The KP25s 
     are polypropylene, internally series connected, 1000+ V/uS rated, and 
     foil terminated.  Everything you'd want in MMC cap!...I think :)
     
     Also also...
     
     I depotted a 15kV, 60ma NST.  I pulled the top off it and roasted it 
     over a Coleman campstove.  The tar above the core softened, but failed 
     to melt, but the tar beneath was boiling!  I finally decided to pull 
     away the upper layer of tar.  In doing so, I pulled off a layer of 
     windings on both secondaries.  While soaking the core in kerosene, I 
     pulled a few more layers of secondary winding.  Is the whole think 
     kaputt?  I'd hate to lose this NST, it was the only 15kV unit I 
     have/had.  I'd be happy with a 14kV, 90ma unit (shunt removal).  Is 
     there a non-obvious reason why pulling a few layers off the 
     secondaries would do anything other than reduce the voltage out?
     
     Bwaahaahaa!
     
     I, Arc